1. Field of the Invention
The invention relates to an insertable tube system for a vacuum cleaner, with at least one first tube, a second tube and with a coupling for detachable connection of the first tube to the second tube, the coupling having a guide element and a lever button, the guide element being located on the outside of the wall of the first tube, the lever button in the guide element being supported to be able to move around a pivot axis, the lever button being movable by the force of at least a first spring element into a catch position, and the lever button on the bottom having a catch projection, and the wall of the first tube can be penetrated by an opening for the catch projection of the lever button, and a mechanical connection between the first tube and the second tube being producible by engagement of the catch projection with a catch recess of the second tube.
2. Description of Related Art
Insertable tube systems for vacuum cleaners are known with a plurality of couplings and catch mechanisms which make it possible to flexibly set the length of the tube system by telescoping of at least two tubes. One design version, for example, according to German Patent DE 197 02 464, calls for a catch element attached to the first outer tube to engage a catch means on the second inner tube, and thus, to block the displacement of the tubes relative to one another.
However, in addition to mechanical fixing of the tubes, dissipation of static voltages should also be ensured; they arise, for example, by the motion of the suction head on the ground or by the air flow. Voltages are conventionally dissipated by the suction head via the metallic tubes of the vacuum cleaner to the handle of the vacuum cleaner; dissipation takes place from the handle of the vacuum cleaner with a suitable means as far as the equipment grounding conductor of an electrical socket. In the prior art, electrical contact-making of the individual tubes among one another—for telescoping tube systems—and also contact-making of the last, upper tube with the handle, often takes place with elastic sliding contacts which are attached to the tube wall and produce an electrically conductive contact with another tube wall.
One major disadvantage of the method known from the prior art for dissipation of static voltages is that a plurality of additional parts for contact-making of the tubes among one another and contact-making of the last, upper tube with the handle must be produced and mounted.